1. Field of Invention
The present invention relates, in general, to active air flap devices for vehicles and, more particularly, to an active air flap device for vehicles which can maximize the aerodynamic performance of a vehicle, thereby increasing the mileage of the vehicle, and can provide a fail-safe function to the vehicle, thereby realizing improved driving safety of the vehicle.
2. Description of Related Art
Generally, an air intake unit that is installed in the front end of a vehicle comprises upper and lower parts separated from each other based on a front bumper back beam. In the related art, active air flap devices that are currently used in the air intake units are classified into the following types of devices.
As shown in FIG. 1, a first type of active air flap device in which one active air flap 1 is installed exclusively in one of the upper and lower parts of the air intake unit is advantageous in that the device has a simple system construction. Another advantage of the first type of active air flap device resides in that a regular cooling surface is formed in a part having no active air flap, and so the active air flap device can provide an improved fail-safe function. However, in the first type of active air flap device, the active air flap is installed in only one of the upper and lower parts of the air intake unit, and so the active air flap device cannot provide a desired air blocking rate, thereby being limited with regards to improvement of the aerodynamic performance and mileage of a vehicle.
A second type of active air flap device, in which respective active air flaps are installed in the upper and lower parts of the air intake unit, with a link connected between the upper and lower active air flaps such that the upper and lower active air flaps can be operated simultaneously using one actuator, is advantageous in that the upper and lower parts of the air intake unit can be opened simultaneously, thereby realizing improved aerodynamic performance of a vehicle when the vehicle is being driven.
However, the second type of active air flap device is problematic in that, when the system of this active air flap device malfunctions in a state in which the upper and lower active air flaps are closed, a user should manually open the flaps after stopping the vehicle and this is inconvenient to the user. Further, the operation of manually opening the flaps is difficult, and so it is not easy to manually open the flaps. Further, when the flaps are not opened, it causes a critical problem in that the vehicle may not be driven.
In the related art, Korean patent application publication No. 10-2012-0106034 proposes “an active air flap”.
However, the technique disclosed in Korean patent application publication No. 10-2012-0106034 is problematic in that it cannot improve the aerodynamic performance of a vehicle, thereby failing to increase the mileage of the vehicle.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.